Prof Teo graduated with a degree in medicine from the National University of Singapore in 1989 and attained his Master of Medicine in Internal Medicine and MRCP (UK) in 1994. He is one of the pioneers of Changi General Hospital and has risen up the ranks to Senior Consultant and Head of Gastroenterology in 2004, Chief of Medicine in 2006, Deputy Chairman of the Medical Board in 2008 and Chairman in 2012 till 2020. He is currently the Chief Executive Officer at Sengkang General Hospital and the Deputy Group Chairman, Medical Board (RHS), Singhealth.
 
While on HMDP training at the University of Michigan Medical Center, he wrote research papers in hepatitis which were published in high impact publications. This has remained his forte as he continues to contribute to scientific journals and conference presentations.

Prof Teo was the President of the Gastroenterological Society of Singapore from 2008-2010 and is currently the Assistant Master and Council Member of the Academy of Medicine Singapore. He holds Professorship from the Duke-NUS Graduate Medical School as well as NUS Yong Loo Lin School of Medicine and is an Adjunct Professor of the Singapore University of Technology and Design. He is also a Clinical Examiner of the PACES/MRCP, MBBS and Duke-NUS examinations.

Prof Teo was the Chief Editor of the Singapore Medical Journal from 2010-2013. He is presently an Editorial Board Member of the Journal of Gastroenterology & Hepatology and also serves as a reviewer for journals like Alimentary Pharmacology & Therapeutics, Singapore Medical Journal, ANNALS, Journal of Medical Virology and Biomedical Central.